Combination electric plug and switch



A. F. HUNT COMBINATION ELECTRIC PLUG- AND SWITCH May 27, 1930.

Filed June 2l, 1927 A TTORNE Y.

Patented May 27, 1930 UNITED STATES UTHlISTi all ALLAN F. HUNT, OF BURLINGAME, CALIFORNIA COMBINATION ELECTRIC PLUG AND SWITCH Application led .Tune 21,

The present invention relates to improvements in switch plugs.

In attaching plugs heretofore provided and wherein switch means have been incorporated, it has been necessary to extend the conducting wires to the plug laterally from the side of the plug surface, rendering it diicult to utilize the plug in a screw socket. In devices of this kind, it has also been the practice to position a rotary switch of the" common type, the operating means of which has been extended from the end of the plug where it is customary to insert conducting wires. These devices have been costly to manufacture due to their complicated structure and numerous parts employed for accomplishing the result desired.

The present invention has for its object to provide a simple switch plug of few parts wherein the conductor wires are led thereto through the end of the plug enabling the ready attachment of the plug to screw sockets. A further object is to rovide a structure wherein the making and reaking of the circuit through the plug is accomplished by a relative coaxial rotation of the plug parts, and wherein the switch or circuit breaking elements engage and disengage through a wiping contact again insuring the completion of the circuit when desired. A further object is to provide means for indicating whether the plug circuit is completed or broken in accordance with the rotative relation of the relatively movable parts. A further object isto provide means for limiting the relative rotation of the movable parts in the making and breaking of the circuit. A further and important object is to provide a switch plug structure which is capable of being cheaply manufactured and assembled, and which is eiiicient for the purpose intended.

In its broadest embodiment, the invention consists in base and cap members united for coaxial rotation, and each mounting conductors fixed thereto adapted on the relative coaxial rotation of the respective parts to engage and disengage and thus make or break the circuit through the plug as desired.

With the above mentioned and other ob- 1927. Serial No. 200,374.

jects in view, the invention consists in the novel construction and combination of parts hereinafter described, illustrated in the accompanying drawings, and set forth in the claims hereto appended, it being understood that various changes in the form, proportion, size and minor details of construction within the scope of the claims may be resorted to` without departing from the spirit or sacrificing any of the advantages'of the invention.

In the drawings Fig. l is a view in elevation of one embodiment of my invention disclosing the switch plug attached to a screw socket member.

Fig. 2 is a vertical sectional view through the structure illustrated in Fig. 1 with the screw socket member removed.

Fig. 3 is a vertical sectional view through the screw socket member.

Fig. 4 is a transverse sectional view on line 4 4 of Fig. 2 illustrating the conducting elements in circuit breaking position.

Fig. 5 is a vertical sectional view of a modified form of structure wherein the cap is in two parts, and wherein the relative axial rotating connection between the base and cap is aiforded by a threaded structure.

Fig. 6 is a transverse sectional view on line 6-6 of Fig. 5.

In the drawings, wherein like characters of reference designate corresponding parts, the numeral l indicates a base of insulating material preferably circular in plan provided on its periphery with a recess 2, terminating at its ends in stop walls or abutments 3. Extending through the base l are the Contact fingers 4 laterally bent at their upper ends at 5 to lie on the upper surface of the base l and project slightly above the same, the side edges of the bent portions 5 being beveled at 6, Fig. 4. Associated with the base 1 is a cap 7 recessed on one face at 8 for the reception of the upper surface of the base 1. The cap is provided with a peripheral flange 9 for overlying the peripheral edge of the base l and the inner surface of the flange is provided with a stop lug 10 for reception within the recess 2, as in Fig. 4 of the drawings. The upper surface of the cap 7 is provided with a central recess 11 into which extend the conductor wires 12, and the side walls of said recess at diametrically opposite points are provided with lateral openings 13 through each of which extends one of said conductor wires 12. The cap 7 carries a pair of conductor plates 14, the lower end 15 of each of which extends into the recess 8, and the upper end of the respective plates is angularly disposed in one of the recesses 13, and at said end carries a binding screw 16 for attaching a conductor wire 12 thereto. Vithin a depression at the base of the recess 11 the cap 7 mounts a nut 17, with which an attaching screw 18 extending axially through the base 1 has threaded connection. The attaching screw 18 affords an attaching means for uniting the cap 7 and base l, and also a means for affording axial rotation between the cap and base. On its periphery, the base 1 is provided preferably with the words On and Off or other suitable wording, which is exposed through the sight opening 19 in flange 9 of cap 7 to indicate whether the circuitthrough the plug is completed or broken.

In Fig. 2 the ends of'the members 4 extend from the base l affording frictional engagement with the contact members 20 of a screw plug base 21 of the usual structure, one of the members 2O being electrically connected with a center contact button 22, and the other being electrically connected with a screw threaded shell 23, the button and shell being suitably insulated from each other.

In the structures illustrated in Figs. 5 and 6, which are designed primarily for employment in connection with those devices having projecting pins for contact terminals, the base 24 of insulating material has tubular conductors 25 extendend therethrough, the same being open at the lower end of the base and closed at 26 at the upper end of the base, the closed ends projecting slightly above the base surface. In this structure the cap consists of two parts 27 and 28 threadedly attached at 29, the member 27 having a conductor wire opening 30 therein which communicates with the chamber 31. The member 28 of the cap mounts tubular contacts 32 extending therethrough, and with each of which is detachably connected one of the conductor wires 33.` A relatively coarse thread connection 34 is provided between the base 24 and the member 28 of the cap, and on the relative axial rotation of the two parts, frictional engagement between the lower ends of members 32 carried by the cap and the upper ends 26 of the members 25 carried by the base 24 are completed or broken, depending on the direction of axial rotation of the respective parts.

It will be observed that this axial rotation of the respective parts, slightly moves the same to and from each other, this being caused by the pitch of the threaded connection 34. To frictionally retain the parts 24 and 28 in their position of relative axial rotation and to limit the relative axial rotation ot' the two parts and also to preclude the complete separation of the two parts, a spring finger 35 is carried on the surface of the base 24, its upper end being received within a recess 36 in the peripheral wall of the member 28 of the cap, said end bearing on the surface of said recess is clearly indicated in Figs. 5 and 6, the ends 37 of said recess affording stops with which the side walls of the finger engages.

In the present construction, it will be apparent that I have provided a switch plug, which in appearance corresponds to the ordinary socket plug now universally in use, and in the same being provided switch means which enable the making or the breaking of the circuit through the plug without detaching the plug from within the attaching socket as is now the custom. I have also provided a switch plug which may be constructed and assembled at little cost, and which may be sold in competition with the common forms of attaching plug now on the market.

1. A combined attaching plug and switch comprising a base of non-conducting material, a plurality of contacts carried thereby and adapted to engage corresponding contact terminals on an attaching member, corresponding ends of said contacts being exposed at one end of the base, a cap of nonconducting material superimposed on and cooperating with one end of the base with the adjacent peripheral edges of said cap and base projecting one over'the other, a rod extending axially through said cap and base for pivotally uniting said cap and base for relative axial rotation, a plurality of contacts carried by the cap and exposed on one face for wiping contact with the exposed face of the base contacts on the relatire axial rotation of the cap and base to make or break the circuit therebetween, cooperating means associated with the cap and base for limiting the relative axial rotation of the parts in either direction, said cap provided with an axial opening for the reception of conductor wires, means for attaching the conductor wires to the cap contacts. and means for indicating the circuit making and breaking positions of the cap and base when relatively axially rotated.

2. A combined attaching plug and switch comprising cooperating cap and base members of non-conducting material, the former provided with a recess extending axially thereinto from one side and terminating at its base in a pair of lateral openings extending through to the opposite face of the cap, a pair of contacts carried by the cap with corresponding ends projecting parallel with said opposite face of the cap and with corresponding opposite ends disposed in proximity to said lateral openings, a pair of contacts carried by the base member and disposed with corresponding portions lying parallel with one face of the base for wiping contact with the portions of the contacts of the cap and at their other ends exposed at the opposite end of the base, an attaching device detachably uniting the cap and base for relative axial rotation to cause said respective pairs of contacts to move into and out ot engagement, said attaching device extending through said cap and base of non-conducting material and being insulated thereb from the contacts, one end of said attaching device being accessible in the base of said cap recess.

3. A combined attaching plug and switch comprising a base member and a cap member, a plurality of contacts carried by the base member, said contacts adapted to engage corresponding Contact terminals on an attaching part, the cap member being superimposed on the base member, one of said members provided with a recess surrounded by an annular flange affording a pocket and into which a portion of the other member extends with the flange projecting beyond its peripheral edge in close operative contact, means connecting the cap and base members to permit relative axial rotation, and a plurality of contacts carried bv the cap member for coaction with the base member contacts on the relative axial rotation of the cap and base members to make or break the cir cuit therebetween.

4. A combined attaching plug and switch comprising a base member and a cap member, a plurality of contacts carried by the base member, said contacts adapted to engage corresponding` contact terminals on an attaching part, the cap member being superimposed on the base member, one of said members provided with a recess surrounded bv an annular flange affording a pocket and into which a portion of the other member extends with the flange projecting beyond its peripheral edge in close operative contact, means connecting the cap and base members to permit relative axial rotation, a pluralitv of contracts carried by the cap member for coaction with the base member contacts on the relative axial rotation of the cap and base members to make or break the circuit therebetween, one of said members having a pair of spaced stops, the other member provided with a lug adapted on the relative axial rotation of the members to cooperate with the stops and limit movement in either direction.

In testimony whereof I have signed my name to this specication.

ALLAN F. HUNT. 

